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J/AJ/125/2502       Spectral indices of Galactic halo        (Morrison+, 2003)

Mapping the galactic halo. VI. Spectroscopic measures of luminosity and metallicity. Morrison H.L., Norris J., Mateo M., Harding P., Olszewski E.W., Shectman S.A., Dohm-Palmer R.C., Helmi A., Freeman K.C. <Astron. J. 125, 2502 (2003)> =2003AJ....125.2502M
ADC_Keywords: Stars, halo ; Spectroscopy ; Magnitudes ; Abundances, [Fe/H] Keywords: Galaxy: evolution - Galaxy: halo - Galaxy: kinematics and dynamics Abstract: We present our calibration of spectroscopic measures of luminosity and metallicity for halo giant candidates and give metallicities and distances for our first sample of spectroscopically confirmed giants. These giants have distances ranging from 15 to 83kpc. As surveys reach farther into the Galaxy's halo with K giant samples, identification of giants becomes more difficult. This is because the numbers of foreground halo K dwarfs rise for V magnitudes of 19-20, typical for halo giants at 100kpc. Our photometric survey uses the strength of the Mgb/H feature near 5170Å to weed K dwarfs out of the disk and thick disk, but we need spectroscopic measures of the strength of the Ca II K, Ca I λ4227, and Mgb/H features to distinguish between the very metal-poor dwarfs and halo giants. Using a full error analysis of our spectroscopic measures, we show why a signal-to-noise ratio of ∼15pixel-1 at Ca I λ4227 and ∼10 at Ca II K is needed for reliable luminosity discrimination. We use the Ca II K and Mgb features to measure metallicity in our halo giants, with typical errors (random plus systematic) of 0.3dex for [Fe/H] values from -0.8 to -3.0. Description: Spectra for halo giant candidates were taken during runs in 1999 May, 2000 January and March on the Kitt Peak National Observatory (KPNO) 4m, 2000 May on the Cerro Tololo Inter-American Observatory (CTIO) 4m, and 2001 February on the Magellan I 6.5m telescope. The Kitt Peak National Observatory (KPNO) 4m data were taken with the RC spectrograph. The KP007 grating was used, giving a resolution of 3.5Å and a spectroscopic range from 3500 to 5900Å. The CTIO 4m data were taken with the RC spectrograph and the KPGL1 grating, giving a resolution of 2.8Å and a spectral range of 3500 to 6450Å. The Magellan I data were taken with the B&C spectrograph, a 600 line grating, a resolution of 2.5Å, and a wavelength range from 3850 to 5300Å. All observations were made at the parallactic angle in order to minimize the loss of UV and blue light from the stars. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 96 18 Metallicity and color of dwarf standards table2.dat 96 49 Metallicity and color of giant standards refs.dat 87 50 References table4.dat 66 17 Spectral indices for dwarf standards table5.dat 66 46 Spectral Indices for giant standards table6.dat 96 94 Spectroscopic Observations for Giant Candidates table7.dat 72 30 Metallicities and distances for spectroscopically confirmed giants
Byte-by-byte Description of file: table1.dat table2.dat
Bytes Format Units Label Explanations
1- 30 A30 --- Name Star name 31 A1 --- n_Name [a] Note on Name (1) 33- 37 F5.2 [Sun] [Fe/H] Metallicity 38 A1 --- n_[Fe/H] [bc] note on [Fe/H] (1) 40- 44 F5.3 mag (b-y)0 ? Dereddened Stroemgren (b-y) colour index 46- 50 F5.3 mag (V-I)0 ? Dereddened Johnson (V-I) colour index 52- 55 F4.2 mag (B-V)0 ? Dereddened Johnson (B-V) colour index 57- 61 F5.3 mag (M-T2)0 Dereddened Washington (M-T2) colour index 62 A1 --- u_(M-T2)0 Uncertainty flag on (M-T2)0 64- 68 F5.3 mag E(B-V) Redenning 69- 83 A15 --- r_[Fe/H] References for [Fe/H], in refs.dat file 86- 91 A6 --- r_(b-y)0 References for photometry, in refs.dat file 92 A1 --- nr(b-y)0 [e] Note on r_(b-y)0 (1) 94- 95 I2 --- r_E(B-V) References for redenning, in refs.dat file 96 A1 --- nrE(B-V) [d] Note on r_E(B-V) (1)
Note (1): Individual notes: a: Chromospherically active star. This makes the K' index unusable because of emission in the core of the K line b: G251-53 is a common proper-motion pair of BD+80 245, which has unusually low α-element abundances, [α/Fe]=-0.3 (Carney et al., 1997AJ....114..363C), compared with the majority of halo stars, which have [α/Fe]~+0.4 c: HD 134440 has low-element abundances, [Ca/Fe]=0.22, [Mg/Fe]=-0.11, King, 1997AJ....113.2302K. e: V-I observations obtained using V magnitude from Cudworth (1979AJ.....84.1312C) and V-I cluster giant branch from Johnson & Bolte (1998AJ....115..693J). d: E(B-V) estimated using Schlegel et al. (1998ApJ...500..525S) reddening, distance estimate, and reduction in line-of-sight reddening from Bond (1980ApJS...44..517B).
Byte-by-byte Description of file: refs.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Ref Reference number 4- 22 A19 --- BibCode BibCode 24- 56 A33 --- Aut Author's name 58- 87 A30 --- Com Comments
Byte-by-byte Description of file: table4.dat table5.dat
Bytes Format Units Label Explanations
1- 30 A30 --- Name Star name 32- 36 F5.2 [Sun] [Fe/H] Metallicity 40- 43 F4.2 mag (M-T2)0 Dereddened Washington (M-T2) colour index 44 A1 --- u_(M-T2)0 Uncertainty flag on (M-T2)0 47- 51 F5.2 mag K' K' index (Beers, 1999AJ....117..981B) 55- 59 F5.2 mag CaI CaI (4227Å) index metallicity measurement 62- 66 F5.2 0.1nm Mg Mg index metallicity measurement
Byte-by-byte Description of file: table6.dat
Bytes Format Units Label Explanations
1- 7 F7.3 deg GLON Galactic longitude (G1) 9- 15 F7.3 deg GLAT Galactic latitude (G1) 17- 21 F5.2 mag Mmag The Washington M-band magnitude 23- 26 F4.2 mag M-T2 The Washington (M-T2) color 28- 32 F5.3 mag e_M-T2 Error in M-T2 34- 37 F4.2 mag C-M The Washington (C-M) color 39- 43 F5.3 mag e_C-M Error in C-M 45- 49 F5.2 mag M-51 The Washington (M-51) color 51- 55 F5.2 [---] [Fe/H]K The K' index metallicity measurement 57- 61 F5.2 [---] e_[Fe/H]K Error in [Fe/H]K 63- 67 F5.2 [---] [Fe/H]CaI The Ca I (4227) index metallicity measurement 69- 73 F5.2 [---] e_[Fe/H]CaI Error in [Fe/H]CaI 75- 79 F5.2 [---] [Fe/H]Mg The Mg index metallicity measurement 81- 84 F4.2 [---] e_[Fe/H]Mg Error in [Fe/H]Mg 86 A1 --- Lum [rgsd] Luminosity classification (1) 88- 90 A3 "month" Obs.M Month of the observation 92- 95 I4 yr Obs.Y ? Year of the observation
Note (1): Luminosity classification: r = Needs repeat observation; g = Giant; s = Subdwarf; d = Dwarf.
Byte-by-byte Description of file: table7.dat
Bytes Format Units Label Explanations
1- 7 F7.3 deg GLON Galactic longitude (G1) 9- 15 F7.3 deg GLAT Galactic latitude (G1) 17- 21 F5.2 [---] [Fe/H]P The photometry-derived metallicity 23- 26 F4.2 [---] e_[Fe/H]P Error in [Fe/H]P 28- 32 F5.2 [---] [Fe/H]S The spectroscopy-derived metallicity 34- 37 F4.2 [---] e_[Fe/H]S Error in [Fe/H]S 39- 43 F5.2 kpc Dist Distance 45- 48 F4.2 kpc e_Dist Error in Dist 50- 59 A10 --- Field Field identification 61 I1 --- Chip Chip number 63- 66 I4 pix Xpix The X pixel coordinate 68- 71 I4 pix Ypix The Y pixel coordinate
Global notes: Note (G1): Objects identified as [MNM2003] LLL.lll+BB.bbb in Simbad
History: From electronic version of the journal References: Morrison et al., Paper I 2000AJ....119.2254M Dohm-Palmer et al., Paper II 2000AJ....120.2496D Hardinf et al., Paper III 2001AJ....122.1397H Morrison et al., Paper IV 2001AJ....121..283M Dohm-Palmer et al., Paper V 2001ApJ...555L..37D
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 16-Jun-2003
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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